Programmer Guide/Command Reference/NEW: Difference between revisions
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{{Programmer Guide}} | |||
The <code>NEW</code> command creates a new [[Programmer_Guide/Shell_Items|shell item]] of the type <var>itemtype</var> and named <var>itemname</var>. | |||
NEW <var>itemtype</var> <var>itemname</var> [ [[Programmer_Guide/Command_Reference_Options/Silent|/I]] ] [ /U|/u ] [ /G ] [ <var>createargs</var> | NEW <var>itemtype</var> <var>itemname</var> [ [[Programmer_Guide/Command_Reference_Options/Silent|/I]] ] [ /U|/u ] [ /G ] [ /Z ] [ <var>createargs</var> [ <var>createopts</var> ] ] | ||
The <code>NEW</code> | The following is applicable to all <code>NEW</code> commands: | ||
*The argument <var>itemname</var> can be set to '<code>*</code>' if the item should automatically be given a unique name (e.g. <code>NEW FILE * /File</code>). | |||
*The name of a new item is always stored in the variable <code>#NEW</code> if the command was successfully completed, otherwise <code>#NEW</code> is set to '<code>*</code>'. | |||
*An item must be deleted (<code>DELETE name</code>) before another <code>NEW</code> command using the same name can be successfully executed. | |||
*<code>NEW</code> commands can be used in inline statements with the syntax <code>#item = $(NEW itemx paramx)</code>. The variable <code>#item</code> is assigned the value of <code>#NEW</code>. Therefore if the command fails, both are assigned the value <code>*</code>. | |||
;<var>itemtype</var>: The type of the new [[Programmer_Guide/Shell_Items|shell item]]. This must be unique (in the item namespace of a shell). | ;<var>itemtype</var>: The type of the new [[Programmer_Guide/Shell_Items|shell item]]. This must be unique (in the item namespace of a shell). | ||
;<var>itemname</var>: The name of the new [[Programmer_Guide/Shell_Items|shell item]]. If this argument is set to the character '''*''', the name is choosen automatically. | ;<var>itemname</var>: The name of the new [[Programmer_Guide/Shell_Items|shell item]]. If this argument is set to the character '''*''', the name is choosen automatically. | ||
;<var>createargs</var>: Arguments specifying parameters for the initialization of the new item. The format and meaning of these arguments are depending on the type of the new | ;<var>createargs</var>: Arguments specifying parameters for the initialization of the new item. The format and meaning of these arguments are depending on the type of the new . | ||
;<code>/I</code>: Enable [[Programmer_Guide/Command_Reference_Options/Silent|silent error reporting]]. If specified, <code>NEW</code> will generate a warning rather than an error if arguments are missing or it is unable create the new item. | ;<code>/I</code>: Enable [[Programmer_Guide/Command_Reference_Options/Silent|silent error reporting]]. If specified, <code>NEW</code> will generate a warning rather than an error if arguments are missing or it is unable create the new item. | ||
;<code>/G</code>: Garbage collection. If specified, a temporary (or local) item created, which is automatically deleted when exiting the macro. | ;<code>/G</code>: Garbage collection. If specified, a temporary (or local) item created, which is automatically deleted when exiting the macro. | ||
;<code>/U</code>: If specified, the global item protection is enabled. This means all items created before this item (called the protection-master) are | ;<code>/U</code>: If specified, the global item protection is enabled. This means all items created before this item (called the protection-master) are protected from being deleted, until the global item protection is disabled, which is done by deleting the protection-master). Protected items can only be deleted using a special option of the <code>[[Programmer_Guide/Command_Reference/DELETE|DELETE]]</code> command. Note: This option is case-sensitive. | ||
;<code>/u</code>: If specified, the created item protected from being deleted | ;<code>/u</code>: If specified, the created item is protected from being deleted, until the global item protection is disabled, which is done by deleting the protection-master). Note: This option is case-sensitive. | ||
;<code>/z</code> | ;<code>/z</code>: Use this option, to create a reference to an already existing shell item (also if owned by another shell). For more details read the section about [[Programmer_Guide/Shell_Items|shell items]] | ||
The following example creates a new table with an automatic name and assigns the name to a local variable or exits if the table was not created. | |||
NEW TABLE * | |||
if '$#new' == '*' then | |||
butil msgbox msg ; Failed to create table | |||
exit | |||
end | |||
#t := $#new$#t * 'my first entry' // append entry to table | |||
You can also use your own name, rather than an automatically generated one. In this case, the code would look like this. | |||
NEW TABLE myTable | |||
if '$#new' == '*' then | |||
butil msgbox msg ; Failed to create table | |||
exit | |||
end | |||
myTable * 'my first entry' // append entry to table | |||
Alternatively, with the inline syntax: | |||
#t := $(NEW TABLE *) | |||
if '$#t' == '*' then | |||
butil msgbox msg ; Failed to create table | |||
exit | |||
end | |||
$#t * 'my first entry' // append entry to table | |||
All instances created with the NEW command should be deleted when no longer needed using the <code>[[Programmer_Guide/Command_Reference/DELETE|DELETE]]</code> command. |
Latest revision as of 15:03, 21 January 2019
The NEW
command creates a new shell item of the type itemtype and named itemname.
NEW itemtype itemname [ /I ] [ /U|/u ] [ /G ] [ /Z ] [ createargs [ createopts ] ]
The following is applicable to all NEW
commands:
- The argument itemname can be set to '
*
' if the item should automatically be given a unique name (e.g.NEW FILE * /File
). - The name of a new item is always stored in the variable
#NEW
if the command was successfully completed, otherwise#NEW
is set to '*
'. - An item must be deleted (
DELETE name
) before anotherNEW
command using the same name can be successfully executed. NEW
commands can be used in inline statements with the syntax#item = $(NEW itemx paramx)
. The variable#item
is assigned the value of#NEW
. Therefore if the command fails, both are assigned the value*
.
- itemtype
- The type of the new shell item. This must be unique (in the item namespace of a shell).
- itemname
- The name of the new shell item. If this argument is set to the character *, the name is choosen automatically.
- createargs
- Arguments specifying parameters for the initialization of the new item. The format and meaning of these arguments are depending on the type of the new .
/I
- Enable silent error reporting. If specified,
NEW
will generate a warning rather than an error if arguments are missing or it is unable create the new item. /G
- Garbage collection. If specified, a temporary (or local) item created, which is automatically deleted when exiting the macro.
/U
- If specified, the global item protection is enabled. This means all items created before this item (called the protection-master) are protected from being deleted, until the global item protection is disabled, which is done by deleting the protection-master). Protected items can only be deleted using a special option of the
DELETE
command. Note: This option is case-sensitive. /u
- If specified, the created item is protected from being deleted, until the global item protection is disabled, which is done by deleting the protection-master). Note: This option is case-sensitive.
/z
- Use this option, to create a reference to an already existing shell item (also if owned by another shell). For more details read the section about shell items
The following example creates a new table with an automatic name and assigns the name to a local variable or exits if the table was not created.
NEW TABLE * if '$#new' == '*' then butil msgbox msg ; Failed to create table exit end #t := $#new$#t * 'my first entry' // append entry to table
You can also use your own name, rather than an automatically generated one. In this case, the code would look like this.
NEW TABLE myTable if '$#new' == '*' then butil msgbox msg ; Failed to create table exit end myTable * 'my first entry' // append entry to table
Alternatively, with the inline syntax:
#t := $(NEW TABLE *) if '$#t' == '*' then butil msgbox msg ; Failed to create table exit end $#t * 'my first entry' // append entry to table
All instances created with the NEW command should be deleted when no longer needed using the DELETE
command.